By Dan Jacobs, Senior Editor, CropLife
It’s estimated there are 1 billion microorganisms in just a teaspoon of soil. Extrapolate that out over the entire farm and the number of things interacting with crops is staggering. It’s little wonder, then, that as much as the industry knows about the importance of soil health, there is still so much more that needs to be learned.
“The soil microbiome is intricately connected to soil health and soil health is the foundation of productive and sustainable agriculture,” says Dr. Holly Little, Director, Research and Development, Acadian Plant Health. “This invisible community of microorganisms can help with nutrient cycling and availability, soil structure and aggregation, soil fertility, and water retention and ultimately plant health as certain microbes produce growth-promoting substances and form symbiotic relationships with plant roots, helping plants withstand environmental stresses.”
In other words, ensuring that what’s seen above ground remains healthy depends on what going on below ground.
“It’s all about adding life to the soil; we want to build underground ecosystems — communities of microbes, fungi, bacteria, worms and more — to promote soil biology all year long, so these ecosystems can rapidly populate and flourish with limited interruption,” says Fred Nichols, Chief Marketing and Chief Sales Officer for Huma. “We do that with our carbon-based solutions. This is what creates a symbiotic relationship between crops and the microbiome.”
While the industry has a deep understanding of that connection, there is plenty more to learn.
“We understand that the microbiome is responsible for supporting the plant life that we focus on growing,” says Keith Byerly, Commercial Sustainability Lead, North America, The Mosaic Co. “The entire scientific community still has a way to go to understand the scale of the microbiome though. There can easily be over 10,000 pounds of living organisms in the top six inches of an acre. We seldom talk about it in this context, but that is similar to supporting eight cows per acre year-round. From industry to agronomists to growers, I don't think we are often thinking about supporting the microbiome at that scale to support the growth of crops yet today.”
The industry has moved well past a focus on traditional soil amendments, says Dr. Ryan Bond, Vice President, Innovation and Business Development, Koch Agronomic Services.
“For many years, growers and researchers have focused on macronutrients, and resulting NPK management practices and applications have helped increase efficiency of fertilizer inputs,’ Bond says. “But there is another dimension to the picture.
“The key to healthy soil and good stewardship is balance,” he continues. That means employing “the right kinds of macronutrients that the plants can access and use; healthy, vibrant microbial populations that are building and improving the soil structure; and vital micronutrients that can further enhance the soil and improve the plant processes that lead us to higher, sustainable yields. Growers and researchers are becoming more attuned to how all these things work together in the microbiome. They’re finding that micronutrients can help a crop function properly and achieve maximum performance.”
Finding a way to keep soil vibrant, healthy, and viable requires the cooperation of manufacturers, retailers, consultants, and growers.
“The microbiome is an ecosystem, just like the woods or the wetlands,” explains The Mosaic Co.’s Byerly. “The diversity of the residents of the ecosystem is a reflection of its health. As stewards of the land, farmers and agronomists are constantly gaining new knowledge on how to maintain a healthy microbiome, because it is a critically important component of water availability, nutrient cycling, mineralization, gas exchange, and much more.”
Why Soil Health is Critical
“It is hard to overstate the importance of the microbiome,” explains Dr. Jacob Parnell, Director of Agronomy, Biome Makers. “When we look at processes on Earth that allow life, so many of these are driven by the microbiome. Although soil microbiome research lags behind gut microbiome research, we can assume a corollary of human health-human gut microbiome exists with planet health-soil microbiome.”
That human/gut analogy is one many manufacturers use to illustrate the importance of microorganisms in the soil.
The soil microbiome is “no different than the microbiome of your body. The soil microorganisms and microbiomes play an important role in many aspects that relate to plant growth including nutrient cycling and soil fertility,” says Stephanie Zelinko, Agronomist for AgroLiquid. “Some of these microbes help release nutrients complexed in the soil to provide essential nutrients for the crop.”
Finding the right mix of organisms helps crops manage a variety of abiotic stress and pests more efficiently than those in less healthy soil.
“Soil serves as a reservoir for many vital environmental microbiomes that are crucial for soil health and fertility,” says Dr. Dhritiman Ghosh, Director of Research and Innovation, Certis Biologicals. “The distribution of these microbiomes significantly impacts soil health. Unfortunately, tillage-based agriculture over the past five decades has disrupted these naturally occurring beneficial microbiomes, creating an urgent need to regenerate the health of affected soils.
“I was part of a team dedicated to developing a product aimed at enhancing soil health by increasing carbon sequestration in the soil,” Ghosh continues. “Here at Certis, we believe that the growing market demand for carbon sequestration will drive us to develop microbial products specifically targeting soil health soon. We are committed to innovating solutions that restore and maintain healthy soil microbiomes, ultimately leading to more sustainable and productive agricultural practices.”
What We Know
One general rule for science is that the more that is learned, the more questions they investigators have. That’s no less true when it comes to the microbiome.
“Notably, it was Robert Koch (a German physician and bacteriologist) close to 150 years ago who defined the connection between microorganisms and disease,” says Koch’s Bond. “We’ve come a long way since then, but there is much to learn about interactions with plants, soil types, and environmental conditions. As an industry, we are interested in current research that will expand our understanding about different microbial species and their potential applications in agriculture.”
And the more that is understood about what constitutes healthy soil, along with what it takes to develop and maintain that health, the more growers are willing to turn that theory into practice.
“There is a shift in the perception of soil health and the microbiome with growers, mainly driven by a growing awareness of the long-term benefits of maintaining healthy soils, the impact of sustainable practices on crop yields and quality, and the influence of environmental concerns,” says Acadian’s Little. “There is now a mindset of farms being ecosystems where soil health is a critical component of farm health and productivity.
“It's a positive trend that promises a more productive future for agriculture,” she continues. “By continuing to support growers, we can ensure that healthy soils remain at the forefront of farming practices.”
Part of knowing what makes soils healthy includes understanding what causes them to degrade.
“Our understanding of soil health is evolving. Farmers have known for a long time that there are certain benefits to converting from tillage to reduced till practices, which includes building the soil organic matter over time,” says AgroLiquid’s Zelinko. “This and other management practices help build a healthier soil over time and can also lead to higher yields. Farmers also generally understand a vital and healthy soil can help their crops withstand environmental threats and suppress disease.
“The complexities around the microbiome make it more challenging,” she continues. “Farmers are asking which bacteria strains or fungi are beneficial and will influence crop yield. As we learn more about the effects the microbiome has on soil and plant health, the perception is becoming more positive. However, with many unknowns I feel the industry still needs more information before truly understanding how they fit in growers’ operations.”
A complete understanding of the microorganisms comprising healthy soil is probably decades away, but that doesn’t mean growers can’t benefit from existing knowledge.
“There's growing awareness of its impact on soil health and crop performance,” Biome Maker’s Parnell says. “The industry's understanding has evolved over the last five years with a more holistic understanding of how the soil microbiome is impacted by different management practices and inputs. On one hand, the soil microbiome is far from well understood; however on the other hand, the tools and technology that industry is using have made some tremendous advancements in what we do understand.”
In addition to yield increases and healthier crops, modern farming techniques are pushing growers to be more aware of the need for healthy soil.
“There has been major progress in this area,” says Mike Powell, Senior Brand Manager of Crop Production with Helena Products Group. “The buzz word is regenerative agriculture (RA). Growers are already using cover crops, reduced tillage and crop rotation, and those practices certainly help the soil microbiome.”
Microbes have always been part of the process. It’s only the industry’s understanding of the role they play in healthy soils that has increased.
“Whether farmers are aware of it or not, they have been farming their soils’ microbiomes along with their crops as long as agriculture has existed,” says Dr. Elizabeth French, Manager, Soil Biology and Bioinformatics, Nutrien Ag Solutions. “So, it’s absolutely foundational to agriculture. Microbes are crucially important for residue decomposition, organic matter formation and mineralization, development of soil structure, and additional nutrient transformations that are key to nutrient availability and loss. For example, microbes govern the processes of nitrification and denitrification, critical N transformation pathways by which nitrogen can be more easily taken up or can be lost from the soil system, depending on environmental conditions.”
According to a 2022 United Nations study, 34% of the world's agricultural land (1,660 million hectares) has been degraded. Another report by the University of Massachusetts Amherst found agricultural fields in the U.S. Midwest have lost about two millimeters of topsoil per year.
“From the very early stage of my career, I was fascinated and intrigued by the microbial world and what [it] can do to the environment and drive other organisms to evolve,” Certis’ Ghosh says. “My favorite example is, when we look at our atmosphere which is full of oxygen, about 4.5 billion years ago there was no oxygen. When cyanobacteria evolved, the oxygen was made, and other oxygen-dependent organisms also evolved. In modern times, we have unknowingly destroyed our environment and are desperately looking for solutions. We figured that ‘microbiome’ is the solution.”
What We Don’t Know
“While understanding in the industry has advanced significantly, the complexity of the soil microbiome continues to challenge scientists worldwide,” Acadian’s Little says. “Despite advances, many soil microbes remain unidentified and poorly understood by the agricultural industry. There is still a lot to learn.”
It’s an exciting (at least important) time to be interested in soil science.
According to Nutrien’s French: “Scientists estimate at the moment that we can culture and study in the lab about 20% of the microbes that we know are there. We know they are there through using sequencing data, but even using sequencing we can only identify 40-50% of the sequences that we find in the soil. So, there is a lot to learn still. Even in the last ten years we have discovered previously unknown groups of microbes that perform important functions in nitrogen transformations in soil, and there is still a lot to learn about what influences their activity and how we can change management practices to promote microbes that conserve nutrients versus those that can cause nutrient losses.”
According to Steve Sopher, Technical Service Manager for Seed and Soil Health, UPL, we’ve only scratched the surface. “We can see what's there and see what they do. But it's harder to know the long-term interactions,” he says. “That's with any interactions between herbicides and [various] products put in the soil. We still have a long way to go before we really understand what we are doing to the soil.”
Huma’s Nichols agrees. “One area we’re exploring is soil exudates. When it comes to the roots, it’s easy to see them operating as a one-way street with water and nutrients going inside the plant. But we’re finding that it’s a busy two-way street. Root exudes make your microbiomes thrive. They add greater biodiversity to your soil and stimulate microbes. We’ve seen this when our carbon-based humates are applied to the soil. Root exudes, along with decaying plant material, serve as the glue that holds soil particles together.”
“Soil enzymes,” says Brian Haschemeyer, Vice President of Discovery of Innovation at BRANDT, “act as indicators of microbial activity and reflect the influence of numerous conditions on the soil microbiome. Therefore, continued studies should be designed to track the kinetics of enzyme activities to understand the effect on overall soil productivity and sustainability.”
Thinking about the vast unknown can be a bit daunting.
“Researchers at Biome Makers have identified over 24 million taxonomic references of microorganisms,” Parnell says. “This extensive research allows us to study the soil microbiome across a wide range of crops and regions, revealing the richness and complexity of agricultural microbiology.”
That richness and complexity will keep soil scientists busy for some time to come.
“You never stop learning, and there is definitely still a lot to learn when it comes to truly understanding the microbiome, especially related to its effects on plant growth,” AgroLiquid’s Zelinko says. “The agriculture industry is getting better each year at understanding the roles and functions of different microbes, which has been an undertaking when you consider there are tens of thousands of species in the soil. Now the need is to better understand how to adjust the populations to better promote crop growth.”
Educating the Industry
“We often will show the economics connected to soil health and a healthy microbiome,” says Acadian’s Little. “In the end, farmers are businesspeople, and the most significant barrier to the adoption of soil health management systems often pertains to profitability. An important study conducted by the Soil Health Institute showed that by using soil health practices farmers were able to increase yield. Across 100 farms in the U.S., soil health systems increased net income for 85% of farmers growing corn and 88% growing soybean (Economics of Soil Health Systems on 100 farms, 2021).”
Success depends not only on the products used, but also on understanding how they work and learning to use them properly. That knowledge varies from country to country and even from farm to farm.
“It depends on who the grower is and what steps they take to keep the soil healthy … whether they're using cover crops, biologicals, or the kind of tillage systems are using,” explains UPL’s Sopher. “Soil [health] can be vastly different from one grower to the next. We do a pretty decent job here [in the U.S.] of maintaining that soil, quality and health.”
Employing the existing understanding of the microbiome along with modern approaches to farming is what it will take to return the world’s degraded soil to a healthier state.
“Advanced crop nutrition is about applying management practices, fertilizers, tools, and technologies to optimize the capability of that connected cropping system,” Mosaic’s Byerly says. “When retailers become accustomed to thinking about soil health, or the soil microbiome in those terms, they often connect it to 4R nutrient management or stewardship. That is a great comparison to make because a healthy soil maximizes and improves soils potential for generations to come.”
And, as with many solutions, it will take time to see that turn around.
“The difficulty lies in the products that are specifically formulated to improve soil health as they may not directly or immediately impact crop yield,” says AgroLiquid’s Zelinko. “With growers already facing difficult markets, this can pose a real economic concern. But we know the long-term impact of increasing the productivity of the soil can have a positive impact on a grower’s bottom line. The question is how the agriculture industry can measure soil health and improve it in a manner that is economically viable. Sustainable agriculture means stewardship of the land, air, and water — but it also means doing this in a way that is profitable over the long term.”
As invested as they are in keeping soils healthy, many growers are reluctant to change their approach if it will decrease profits.
“The simplest way to educate is on the basics of how the microbiome impacts the retailers/growers directly,” explains Derek Emerine, National Agronomist with Helena Agri-Enterprises. “Give the basic background of the role the microbiome can play and give examples of particular products improving yield, nutrient use efficiency, or both.”
Returning the microbiome to a healthy state requires a long-term view.
“Understanding the microbiome helps identify biological bottlenecks in soil health, such as nutrient deficiencies or disease risks, which can otherwise limit yields and increase input costs,” says Biome Makers’ Parnell. “By making data-driven adjustments based on microbiome insights, growers can optimize their use of biological products and traditional inputs more efficiently.
“There's been a notable shift from viewing soil as a mere growing medium to recognizing it as a dynamic ecosystem,” he continues. “Growers increasingly understand the microbiome's role in achieving nutrient-dense, resilient cropping systems.”
Ongoing education is key.
“We educate retailers and growers through workshops, field demonstrations, and data showcasing the benefits of our enzyme-based products,” BRANDT’s Haschemeyer says. “By highlighting how BRANDT EnzUp technologies improve soil health and crop performance, we underscore the importance of maintaining a healthy microbiome.”
Nutrien takes a similar approach.
“We have developed and incorporated training on soil health and microbiology into all of the trainings that our training team uses to train our crop consultants on key agronomic topics, so that they are able to be trusted agronomic advisors to our grower-customers,” says Nutrien’s French. “I find telling good stories and making analogies to explain the importance of the microbiome are key to getting the message across. For example, most people understand that the microbiome in our gut is key to our health — soil microbes play very similar roles for plants, helping to ‘digest’ or make nutrients available and protecting from disease.”
One of the biggest challenges has less to do with ignorance than it does with apathy — or at least with tradition.
“The perception of the microbiome among retailers and growers has been evolving slowly, particularly regarding soil health,” Certis’ Ghosh says. “Much of agriculture still relies on tillage practices that harm the natural soil microbiome, turning fertile soil into mere dirt. We need to continue to raise awareness among growers that crop rotation and the use of organic fertilizers can sustain the natural soil microbiome, leading to more sustainable productivity.
“With growing awareness, research, and evidence of its benefits, the soil microbiome is now recognized as a crucial factor in sustainable agriculture,” he continues. “Retailers and growers increasingly appreciate the role of microbial products in unlocking soil nutrients for plant uptake, enhancing soil health, reducing reliance on chemical inputs, and improving crop performance. While microbial products targeting bionutrition indirectly support a healthy soil microbiome, there is an urgent need to develop products that can rejuvenate degraded soil back to health.”
Changing Understanding
Necessity, as the saying goes, is the mother of invention. A corollary to that cliche could be stated as: Desperation is the father of innovation. When supply chain disruptions caused fertilizer prices to skyrocket, growers looked for ways to cut costs without diminishing yield. Enter micronutrients.
“What happened in 2022 opened growers’ eyes like never before, as they opened their wallets like never before,” Huma’s Nichols says. “This motivated them to actively search for alternatives. Consequently, we’re seeing an unprecedented interest in our carbon-based, humic products.
“We’re experiencing a paradigm shift when it comes to soil health,” he continues. “It used to be that farmers would take a defensive approach. They viewed their soil primarily as something that needed protecting, generally via soil conservation methods. And this is still important. But now, farmers are going on the offensive when it comes to soil health. They are proactively looking for practices and products to optimize nutrient bioavailability, reduce crop input costs, improve water infiltration and moisture retention, and ultimately improve yields. We’re helping change mindsets so that growers focus on farming the soil and not just the crop.”
Whether it was necessity, desperation, or simply understanding, the conversation around the microbiome has shifted.
“I think the approach/discussion around soil health products has changed from ‘Do these products actually work?’ to ‘I know the products have the potential to work, but will they work on my farm?’” says Helena’s Emerine.
Like traditional crop inputs, any new product must be tested for efficacy.
“One of the questions that is always at the top of our mind is what impact positive or negative will a potential solution have on the soil microbiome,” says Mike Zwingman, Director of Agronomy for Verdesian Life Sciences. “Additionally, we are always evaluating new technologies and methodologies that help us gain a greater understanding of both function and characterization of the soil microbiomes we are working with.
“The perception has changed from something we can’t do much about to how can we learn and adapt our practices to harmonize with the soil system to maximize productivity as we reduce our footprint on the system,” Zwingman continues.
The role the microbiome plays in contributing to healthy crops isn’t only about amending the microbiome. It’s understanding how all the myriad microorganisms and the products that are added work together.
“The perception has shifted. Retailers and growers increasingly understand both macro- and micronutrients as essential for long-term soil health and profitability,” says Koch’s Bond. “It’s also been interesting to see shifts toward soil health as seed and plant genetics have grown yields to points that hit max results without adjustments to soil health. Something has to feed those record yields.”
The latest technologies (read Artificial Intelligence) permeate many aspects of business, and the ag industry is no exception.
“Our approach has shifted towards precision and efficacy,” Biome Makers’ Parnell says. “We now integrate advanced genomic and data analytics with AI and machine learning to provide tailored soil health recommendations that optimize microbial communities for specific crops and soil conditions.
“Additionally, our approach is to democratize soil biology information,” Parnell continues. “We want to make data that has traditionally been available to research and industry accessible to farmers. We want them to be informed about how the decisions they are making impact the biology of their soils.”
According to Helena’s Emerine, “There is much more openness to the fact that products meant to improve the microbiome can potentially work. There is less debate about the potential of these products, but more questions on will they work in specific areas.”
Nutrien’s French sums up the manufacturers’ role in developing healthy soils.
“We believe we are at the front end of a new era in agricultural efficiency, and we will achieve these gains through a better understanding of the whole soil environment,” she says. “Our approach is to integrate information about the soil — the biology, chemistry, physical aspects along with the weather and management — to be able to make the best recommendations possible.”
Photo credit: Koch Agronomic Services
